Retrofit2 + RxJava2 + RxAndroid error

Question

I am getting error message as below when try to crate Subscriber and subscribe.

can not resolve method 'subscribe(anonymous rx.Subscriber<GooglePlacesResponse>)'

build.gradle

// JSON Parsing
compile 'com.google.code.gson:gson:2.6.1'
compile 'com.squareup.retrofit2:retrofit:2.1.0'
compile 'com.squareup.retrofit2:converter-gson:2.1.0'
compile 'com.squareup.retrofit2:adapter-rxjava:2.1.0'
compile 'io.reactivex.rxjava2:rxjava:2.0.2'
compile 'io.reactivex.rxjava2:rxandroid:2.0.1

GooglePlaceService.java

public interface GooglePlaceService {

    public static final String GOOGLE_API_KEY = "google_api_key";

    @GET("maps/api/place/nearbysearch/json?radius=2000&key="+GOOGLE_API_KEY)
    Observable<GooglePlacesResponse> getNearbyPlaces(@Query("location") String location);
}

ApiUtils.java

public class ApiUtils {    

    public static final String GOOGLE_PLACE_BASE_URL = "https://maps.googleapis.com/";

    public static GooglePlaceService getGooglePlaceService() {
        return getClient(GOOGLE_PLACE_BASE_URL).create(GooglePlaceService.class);
    }

    public static Retrofit getClient(String baseUrl) {

        Retrofit retrofit = new Retrofit.Builder()
                .addCallAdapterFactory(RxJavaCallAdapterFactory.create())
                .addConverterFactory(GsonConverterFactory.create())
                .baseUrl(baseUrl)
                .build();

        return retrofit;
    }
}

Observable Observable<GooglePlacesResponse> is as below.

Observable<GooglePlacesResponse> mGooglePlacesResponseObervable = ApiUtils.getGooglePlaceService().getNearbyPlaces(latitude + "," + longitude);

mGooglePlacesResponseObervable
   .subscribeOn(Schedulers.io())
   .observeOn(AndroidSchedulers.mainThread())
   .subscribe(new Subscriber<GooglePlacesResponse>() { <-- Error here : can not resolve method `subscribe(anonymous rx.Subscriber<GooglePlacesResponse>)`

            @Override
            public void onNext(GooglePlacesResponse googlePlacesResponse) {

                }

            @Override
            public void onCompleted() {

            }

            @Override
            public void onError(Throwable e) {

            }
     });

Answer 1

The fact that adapter has version 2.*.* does not mean that it is intended for use with RxJava 2

You should use the official adapter for the second version of RxJava:

implementation 'com.squareup.retrofit2:adapter-rxjava2:2.3.0' // works with RxJava 2

Then you can add factory:

Retrofit retrofit = new Retrofit.Builder()
    .baseUrl("https://api.example.com")
    .addCallAdapterFactory(RxJava2CallAdapterFactory.create())
    .build();

Here is the full answer.